I'm still new to brewing (2 batches in) and I've hit a snag. This batch is a Dunckelweizen made from a recipe found on the internet. the Recipe had decent instructions up to the end of the boil, and did not include the expected final gravity. i left it to ferment for a full week (fermented fast at first and slowed after 4 days. after 7 days fermentation seemed to have stopped, so I added 3/4 cup priming sugar and bottled it. after aging for 6 weeks, the beer tastes great, but is very foamy. pours as more foam than beer. What went wrong? too much priming sugar, did I bottle it too early, some sort of contamination? Please help.

Your problems could possibly be from contamination, but I'm going to lean more towards it was bottled too early.
One week in the fermenter seems a little quick to bottle. Don't assume just because the airlock is not bubbling anymore, that it is finished. The only real way to tell if it's finish fermeting is using a hydrometer.

But a safe and easy way to that is to leave it in the fermenter at least 2 weeks. You should be safe by then(depending on the temerature).
I've started leaving mine in the fermeter for 3 weeks. By doing this, it does a few things. One, it gives more time clarify the beer. Secondly, leaving it on the yeast helps speed up some of the clean up. Fermentation produces byproducts that give your beer off flavors. When fermentation is complete, the yeast cleans these up. If you bottle quickly, the small amount of yeast left in the bottle takes it longer to do the cleaning process.

Correct. I don't bother with the secondary. It works fine with no problems.

There are many opinions on how long you should leave it in the primary. Some will say that leaving it on the big yeast cake will cause autolysis. Others will disagree and say autolysis takes much longer to occur than just weeks.

As with me, I'm finding it beneficial. My beer has time to clarify, the yeast cleans up all the "green" beer flavors faster and I don't have to mess with cleaning or racking into a secondary.

I generally do the same as Legman unless I have a compelling reason to perform a secondary for a particular recipe, which is rare.

I agree, 1 week is almost certainly too early to bottle. I've only done this once, when I had an Ordinary Bitter that seemed to finish in only 3 days. It was the only batch I ever had a problem with gushers.

ihawks, when I first started brewing, I over primed a batch and eventually had all gushers. To save the batch, I took all of the bottles and refrigerated them very cold.
Then I opened all the bottles for about 10 min. and let them foam out a bit. Recapped them all and back in the fridge. This was enough to let out the excess pressure and I saved the rest of the batch. From there on out, the rest of the beers were fine. You lose a bit from each bottle, but over all, it wasn't too bad. That was a lesson learned. I'll never do that again.

You may want to try this and see if it works for you.
The most important thing is, that you were probably pretty luck you didn't get a whole batch of grenades! This can be very dangerous. Be careful next time.

It takes time to complete the fermentation process. Every beer is different as there is a direct correlation to the quantity/ quality of yeast pitched, temperature fermented and amount of fermetables extracted from the grains (all grainers). This being said, watch your air lock. When it slows/ stops take a gravity reading for a few consecutive days. If it stays the same and you are at or near your expected final gravity, you can move to bottling. Check the CO2 level for style and use the appropriate quantity of priming sugar. There are programs/ tables on the net to help. Note: The pro's go by weight not volume. Ensure that the priming sugar is thoroughly mixed in the bottling bucket. Most boil it with a few cups of water but make sure you stir the bucket without introducing much O2.